Page signal for typewriters



PAGE SIGNAL FOR .TYPEWRITERS Filed-May 21, 1928 2 Sheets-Sheet 1INVENTOR wvrusss xn-bmisv Jan. 19,1932. DAVIS 1,841,588

' PAGE smug FOR TYPEWRITERS 8 Filed May 21. 1928 2 Sheets-sheet 2 J1)Jaw's INVENTOR Patented Jan. 19,1932

JIM DAVIS, 01? JOPLIN, MISSOURI PAGE SIGNAL FOR TYPEWRITERS Applicationfiled May 21, 1928. Serial'No. 279,561.

This invention relates to signals for typewriter sheets. In operating atypewriter the typist very often shifts the paper carrying I the typematter when the bottom of the sheet has been shifted out of alinementwith the striking ends of the type, thereby leaving a smudge of ink onthe rubber platen roller as well as effecting a loss of time on the partof the operator. The present invention w is designed to avoid thisdifliculty by mounting asignal device on the machinewhich calls theattention of the operator to the fact that the end of the sheet has beenreached and that a new sheet should be introduced into m the machine.

In carrying out the inventlon I mount on the machine over the paper, asignaling device preferably one producing an audible alarm as by anelectric vibrator, the signal 29 being efiected by a spring actuatedcircuit closer, the two contacts of which are automatically broughttogether when the end of the paper sheet has been shifted to the finalrecording line. When the paper is placed in the carriage it holds openthe contacts, there.- by preventingthe vibrator operating so long as thecontacts have the paper film between them, and when the paper has beenshifted to bring the sheet out of alinement with the 30 striking end ofthe type bars it will no longer intervene between the parts of thecircuit closer to hold them open and prevent'contact, thereby closingthe circuit and operating the vibrator.

In order to keep the vibrator from action when the paper is not inplace, as in the normal condition of the machine, by which an alarmwould be in the operating room as well as exhausting the energy of thesource of elec- 40 trcmotive force or battery, I provide an auxiliaryswitch in series relation to the vibrator circuit-by which it may bekept closed when the operator is writing, and latched by the escapementof the carriage. The auxiliary key opens the gravitative auxiliaryswitch and latches it in open position and the escapement of thetypewriter recloses it in order that when the end of the page isreached,

"the circuit closer controlled by the paper and held open thereby passesout of contact with the paper and its two contacts come together toactuate the alarm.

My invention therefore comprises a signal depending upon theintroduction of paper in a typewriter actuated by the transit of thepaper out of register with the types to indi cate that a new sheet mustbe introduced] It comprises also an audible alarm in the form of aVibrator controlled by a circuit closer, the two contacts of which areseparated on introduction of a paper sheet.

It comprises also other specific features, the novelty of which will behereinafter de scribed and will be definitely indicated in the appendedclaims.

Referring now'in detail to the drawings-- Figure l is an elevationillustrating the application of my device to a standard typewriter.

Figure 2is a side elevation partly diagrammatic of the invention Figure3 is a sectional detail of the circuit closer controlled by the paperfilm- Figure 4 is a front view of the circuit closer shown in Figure 3.

Figure 5 isan elevation of an auxiliary switch 4 Figure 6 is an end viewof the switch shown in Figure 5- Figure 7 is an isometric view of theescapement c0ntroller Figure 8 is a sectional View of a mountingclampfor an auxiliary key Figure 9 is a front view of the clamp ofFigure 8. 5 Referring now in particular to the draw- 1ngs-Figures 1 and2 represent in dotted lines the outline of the parts of a standardmachine, the full lines indicating the attached parts constituting myinvention-1 repre- 9 sents a rod mounted on the paper guide of thecarriage supported in a pair of brackets. A curved metallic strip 2 ismounted in a fibre support attached to the rod 1. The paper guide 4forms an arched segment enclosing the lower portion of the cylindricaltype platen which is the usual construction found on standard machines.My insulated arm 2 conforms in shape to this arched paper guide, and isformed of a piece of elastic spring metal, normally tending to form acontact with the bottom of a paper support 4, but when a sheet of paperis introduced between platen and the paper guide the elastic blades areseparated by the insulating film of paper. The insulated strip 2 isconnectedwith a wire 5 in circuit with a buzzer 6, and an auxiliaryswitch pivoted in a bracket on the base of the machine havinga circuitclosing arm 8 and a weighted arm 9, tending to shift it normally intoengagement with a cooperating contact formed by two blades 7, by which awire connection is made with a binding post of a source of electricmotive force as a battery 19, grounded on the machine at 20. Anauxiliary key 11 controlled by a tension spring 11a is mounted by a clip12, on a rod 11 at the base of the machine and when the key is depressedthe key raises the arm 13 and shifts the switch arm 9 to open relationto the contact 7. A spring 17 normally maintains a rod 16 in engagementwith escapement 18 of the typewriter; this rod is mounted rotatably onthe base of the typewriter in a pair of brackets and carries an an lararm 14 having a right-angled bend in its top to latch the cam 10 andhold the switch in open posi-.

tion,but when-the typewriter is in action the movement of the escapementlever 18 rocks the arm 15 thereby disengaging the latch arm 14 andpermitting the arm 9 to depress the switch into closed relation by theweight of the arm.

In operation, a sheet of paper is inserted in the typewriter in theordinary manner and breaks the circuit to the alarm 6 by spacing thecontact strip 2 from the paper support 4 of the typewriter, it beingunderstood at this time the switch 8 is disengaged from the contacts 7and held in this position by the end 14 of the rod 15 engaging under thelower edge of the cam 10, which edge is ofiset laterally of the oppositeedge of said cam. The first operation of any. one of the keys or spacingbar of the typewriter causes the rod 15 to be rocked by the escapement18 of the typewriter which disengages the end 14 of said rod 15 from thelower edge of the cam 10, freeing the switch 8 and the latter gravitatesto circuit closing position or in engagement'with the contacts 7 underthe weight of the cam .and arm 9. The end 14 of the rod'15 is thendisposed opposite the outer face and adjacent the upper edge of the camwhich permits the rod 15 to rock freely .under the influence of theescapement 18. When the sheet of paper has been fed through thetypewriter or the entire surface of the paper typed on, the paper hasmoved from between the strip 2 and the paper holder 4 and the strip 2engages the older 4 completing the circuit to the alarm Warningtheoperator against further use of the typewriter until'another piece ofpaper has been placed therein. To stop the alarm,

the operator presses the key 11 which raises the arm 9 through the arm13 and disengages the switch 8 from the contacts 7 and simultaneouslypositions the cam 10 that the end 14 of the rod 15 engages under thelower edge of the cam and supports the switch 8 in circuit breakingposition. The device is then ready for further operation in the mannerheretofore described.

Having thus described my invention, what I claim is new and desire tosecure 'by Letters Patent is 1. A signal for typewriters including acircuit closing means controlled by the paper in a typewriter and analarm in circuit with said means and electrical source, spaced contactselectrically connected to the electrical source and the alarm, a gravityactuated switch for bridging said contacts, an arm movable with theswitch, a cam carried by the arm, means to engage the cam for holdingthe switch in a position to disengage the contacts and actuated by theescapement of the typewriter to free said switch and permit the latterto gravitate into engagement with the contacts, and means under thecontrol of the operator to disengage the switch from the contacts andsimulta eously position the cam to be engaged by sai second means tosupport the switch in an elevated position.

2. A switch for typewriters including a circuit closing means controlledby the paper in a typewriter and an alarm in circuit with said means andan electrical source, spaced contacts electrically connected to theelectrical source and the alarm, a gravity actuated switch for bridgingsaid contacts, an arm movable with the switch, a cam carried by the arm,a pivoted rod having angularly related arms and one of said arms toengage the cam for holding the switch in a position to disengage thecontacts and the other arm to be enga ed b the escapement of thetypewriter to ree t e switch and permit the latter to gravitate intoengagement with the contacts, and means under the control of theoperator to disengage the switch from the contacts and simultaneouslyposition the cam to be engaged by one of the arms of said rod to supportthe switch in an elevated position.

3. A signal for typewriters including a circuit closing means controlledby the paper in'a typewriter and an alarm in circuit with said means andan electrical source, spaced contacts electrically connected to theelectrical source and the alarm, a gravity actuated switch for bridgingsaid contacts an arm movable with the switch, a cam earned by the arm, apivoted rod having angularly related arms and one of said arms to engagethe cam for holding the switch in a osition to disengage the contactsand the ot er arm thereof to be engaged by the escapement of the typeWriter to free the switch and permit the latter to gravitate intoengagement with the contacts, and a pivoted rod having an angularlyrelated portion disposed adjacent the first arm, and a key carried bythe other end of the last mentioned rod to be actuated to disengage theswitch from the contacts and position the cam to be engaged by one ofthe arms of the first mentioned rod for supporting the switch in anelevated position.

In testimony whereof I, aflix my si ature.

JIM D VIS.

